促红细胞生成素对窒息新生大鼠脑组织Omi/HtrA2表达水平及细胞凋亡的影响

Effects of erythropoietin on expression of Omi/HtrA2 and neuron apoptosis in brain of neonatal rats after asphyxia.

【目的】探讨促红细胞生成素(erythropoietin,EPO)对常压窒息新生大鼠脑组织内Omi/HtrA2表达水平及细胞凋亡的影响。【方法】7日龄新生SD大鼠随机分为对照组、窒息组和EPO干预组(每组n=25)。对照组模拟窒息过程但不缺氧,窒息组和EPO干预组制备新生大鼠常压窒息模型,EPO干预组窒息模型制备后即刻腹腔注射重组人促红细胞生成素5 000U/kg,对照组和窒息组均注射同体积生理盐水。各组于造模后不同时间点(6、12、24、48、72h)取脑组织行石蜡切片,HE染色观察脑组织病理改变,TUNEL法检测神经细胞凋亡,免疫组化法检测Omi/HtrA2表达。【结果】窒息组脑组织Omi/HtrA2的表达和凋亡细胞数在各时间点均高于对照组(P均<0.05),而EPO干预组同窒息组比较,各时间点凋亡细胞数和Omi/HtrA2表达均显著下降,其差异均有统计学意义(P均<0.05),但均未恢复至对照组水平(P<0.05)。【结论】EPO可能通过抑制脑组织Omi/HtrA2的表达而减少神经细胞的凋亡,从而对窒息脑损伤起到保护作用。

[Objective] To investigate the expression of Omi/HtrA2 and cell apoptosis in brain of neonatal rats after asphyxia and to evaluate the effects of erythropoietip （EPO） on it. [Methods] These SD rats aged 7 days were randomly divided into the following groups：control group,asphyxia group and EPO treatment group. Animals of asphyxia group and EPO treatment group were reproduced by normobaric asphyxia,then EPO treatment group immediately injected the rhEPO （5 000 U/kg） in intraperitoneal immediately after asphyxia, the control group and asphyxia group were injected the same volume of 0.9% sodium chloride,then the brain tissues from the rats in the both groups were taken at 6,12,24,48 and 72 hours after the asphyxia. The pathological changes of brain tissue observed by HE staining , the apoptotic cells were detected by the TUNEL staining method and the Omi/HtrA2 protein expression was detected with the immunhistochemistry meth- od. [Results] In asphyxia groups,the number of apoptotic cells and the expression of Omi/HtrA2 were higher than those in control group at each time group （P〈0.05）. But compared with asphyxia group, the number of apoptotic cells were higher and the expressions of Omi/HtrA2 were significantly decreased in EPO treatment group,and the differences were significant（P〈0.05） ,but all parameters were not restored to the level of control group（P〈0.05）. [Conclusion] EPO can reduce the number of apoptotic cells by inhibiting the expression of Omi/HtrA2 in brain,and thus can play a protective role in asphyxia brain damage of neonatal rats.